Hi, I’m Mark!

I'm an expert at every layer of the web stack:

  • Agentic AI chatbots
  • TLS cryptography algorithms in C
  • deploying networked Linux VPSs
  • Python/Go/JS/C routes and SQL databases
  • custom HTML video players with canvas
  • TypeScript/React components

I've worked with Duolingo, Indeed, Thumbtack, and more on products used by millions of users.

I've also built native cross-platform apps for macOS, Windows, Android, and iOS, and done graphics programming in Vulkan, Direct3D, and Metal.

After graduating CMU and doing my rounds of the big tech companies, I found I could best leverage my agency working as an independent consultant. My strength lies in an empathetic approach to existing codebases and a love of simplicity and performance.

Mark is an incredibly talented and efficient engineer. He has impeccable craft and can build sites at a very high bar at impressive speeds. He helped me bring my design portfolio to life, creating custom media controls, implementing unique transitions and more. What I love the most about Mark is his attention to detail. He will go the extra mile to get it perfect. He is a product designer's dream to work with!

Clearly AI

BAML, AI, React, Python
First engineer hire of YC AI startup
Built AI agentic chatbot including tool integrations across ServiceNow and other 3rd party services. Added source citations for AI responses with original document excerpt preview. Made novel markdown diffing frontend for reviewing agentic AI changes. Created frontend from scratch. Wore many startup engineer hats and met with customers.

Duolingo Plus Web

React, Python, Stripe
Web version of Duolingo subscription
Implemented web frontend based on design. Architected and built Python backend with Stripe integration for subscription management.

ayademler.com

JS, HTML, sh, ffmpeg, Cloudflare
Designer portfolio site with custom chunked video player
Implemented web frontend based on design. Created novel canvas-based video player with custom prefetching algorithm for instant video loads. Set up Cloudflare pages site for free hosting.

Pebblestream

Clojure, Java, C#
Compiler and runtime for high-performance Excel spreadsheet computing
Optimized and extended compiler and runtime to enable a "Big Four" accounting firm to run one billion tax computations every month while retaining their core logic in Excel spreadsheets.

Mobile phone code editor

Android, iOS, C, Vulkan, Metal
Code editor / IDE with novel features for mobile phone
Designed and built from scratch a cross-platform app using a C native library, rendering directly to a Vulkan/Metal surface, including custom text layout and rendering, autocorrect, and code formatting.

Custom code diff resolver

C, macOS, Metal, diff algorithms
Mac program to interactively diff code files
Researched and implemented a novel diff algorithm from scratch to allow parallel independent development of similar codebases (e.g. two platforms of the same program) without constraining them to a shared interface library.

Webassembly debugger for Chrome

C, JS, DWARF, Windows
DWARF web assembly debugger
After feeling frustration with Chrome’s webassembly debugger, I wrote a new one from scratch with instant stepping, communicating with Chrome over the Chrome DevTools Protocol.

TLS 1.2 Server

C, cryptography
From scratch TLS server, no openssl etc
Implemented a TLS 1.2 server that was successfully used to host a HTTPS site from scratch without the use of existing libraries (such as for RSA signing).

SSH with SFTP basic client

C, SSH
SSH and SFTP client from scratch
Implemented a minimal SSH client without libraries which could also use SFTP to get and set files from a VPS.

Browser automation for bank data

C, Chrome DevTools Protocol
Automatic bank logins and data download
Wrote a windows program which connected to chrome via Chrome DevTools Protocol and automated the login and transaction downloading of five different websites.

PDF renderer with Excel formulas in the browser

JS, HTML, PDF, Canvas
Wrote a web program for doing my own taxes that would parse tax form PDFs without a library, render them into an HTML canvas, and allow entering values that referenced other values in the form.

Financial simulator in the browser

JS, C, WebSockets, HTML
Wrote a web program which simulates arbitrary financial events defined via Excel-esque formulas. Live sync across multiple users.

AI Copilot for the shell

C
Wraps shell programs to give AI completions
Created a program which wraps standard input and output of a program to offer GitHub Copilot-powered autocomplete suggestions transparently while typing input to the program.

WebGL expense organizer

JS, C, WebGL
Made a tool in C compiled to WebAssembly which runs in the browser via WebGL. It shows a series of expenses, waits for the user to tap the category they belong to, and finally syncs to a server for further processing.

JSON viewer with transparency

C, Windows
Made a program which listens for a global keyboard shortcut and displays the copied JSON in an interactive viewer. The viewer is transparent apart from the content and sticks to the top of the screen for easy use while debugging.

Windows remote file system (projected)

C, Windows
Made a Windows daemon which talks to a TCP server and presents a file from that server as a regular file via ProjFS.
Education: Bachelor's of Computer Science and Arts at Carnegie Mellon University